Strain reliever for a lead of an implantable heart stimulator

Abstract

A strain reliever for a lead of an implantable heart stimulator, the lead including at least one cable having an electric conductor, has a body of electrically conducting material in electric contact with the electric conductor. The body is lockable in a position in electric contact with electric circuitry of the heart stimulator. The body has a fastening arrangement for fastening the proximal end of the cable at the fastening point on the peripheral surface of the body located at a distance from the distal end of the body. A fixing arrangement is provided at the distal end of the body for fixing the cable to extend in the distal direction from a departure point at the body distal end. The cable is intended to extend in a helical path on the peripheral surface of the body between the fastening point and the departure point.

1. A strain reliever for a lead of an implantable cardiac stimulator, said lead including at least one electric cable having an electrical conductor, said strain reliever comprising:
 a strain reliever body comprising electrically conducting material configured to be in electrical contact with said electrical conductor, said strain reliever body being configured to be locked in electrical contact with electrical circuitry of the cardiac stimulator; 
 a fastener configured to fasten said strain reliever body to a proximal end of the cable at a fastening point on a peripheral surface of the strain relieve body located at a distance from a distal end of said strain reliever body; and 
 a fixing arrangement at a distal end of said strain reliever body that fixes the cable to extend in the distal direction from a departure point from the distal end of the strain reliever body, and causing said cable to extend in a helical path on a peripheral surface of the strain reliever body between the fastening point and the departure point. 
 
     
     
       2. A strain reliever as claimed in  claim 1  wherein said strain reliever body is substantially cylindrical. 
     
     
       3. A strain reliever as claimed in  claim 1  wherein said strain reliever body has a helical groove in said peripheral surface proceeding along at least a portion of a longitudinal length of said strain reliever body, said groove ending at said departure point at said distal end of said strain reliever body, and said groove being configured to receive at least a portion of the proximal end of said cable. 
     
     
       4. A strain reliever as claimed in  claim 3  wherein said groove extends from said departure point along a portion of a distance to said fastening point. 
     
     
       5. A strain reliever as claimed in  claim 3  wherein said groove extends from said departure point at least to said fastening point, and wherein said fastening point is located in said groove. 
     
     
       6. A strain reliever as claimed in  claim 3  wherein said groove is inclined toward said distal end of said strain reliever body by a predetermined angle. 
     
     
       7. A strain reliever as claimed in  claim 6  wherein said predetermined angle is 30°. 
     
     
       8. A strain reliever as claimed in  claim 3  wherein said groove extends along at least one turn around the periphery of said strain reliever body. 
     
     
       9. A strain reliever as claimed in  claim 1  wherein said fastener is a weld. 
     
     
       10. A strain reliever as claimed in  claim 1  wherein said strain reliever body is comprised of an electrically conducting stainless alloy. 
     
     
       11. A strain reliever as claimed in  claim 10  wherein said strain reliever body is comprised of a Co—Ni—Mo—Cr alloy. 
     
     
       12. A strain reliever as claimed in  claim 1  wherein said body is configured to receive multiple, helically proceeding cables substantially in parallel on said peripheral surface between said fastening point and said departure point. 
     
     
       13. A lead for an implantable cardiac stimulator comprising:
 an electrical cable containing an electrical conductor; and 
 a strain reliever comprising a strain reliever body comprising electrically conducting material configured to be in electrical contact with said electrical conductor, said strain reliever body being configured to be locked in electrical contact with electrical circuitry of the cardiac stimulator, a fastener configured to fasten said strain reliever body to a proximal end of the cable at a fastening point on a peripheral surface of the strain relieve body located at a distance from a distal end of said strain reliever body, and a fixing arrangement at a distal end of said strain reliever body that fixes the cable to extend in the distal direction from a departure point from the distal end of the strain reliever body, and causing said cable to extend in a helical path on a peripheral surface of the strain reliever body between the fastening point and the departure point.